Sheet metal tubular exhaust gas element deformed to provide elbow



y 1966 M. c. CURTIS ETAL 3,259,149

SHEET METAL TUBULAR EXHAUST GAS ELEMENT DEFORMED TO PROVIDE ELBOW Filed Nov. 12, 1964 INV NTORS- United States Patent 3,259,149 SHEET METAL TUBULAR EXHAUST GAS ELE- MENT DEFORMED TO PROVIDE ELBOW Myron C. Curtis, Chelsea, and Eldred G. Straw, Grass Lake, Mich., assignors to Walker Manufacturing Company, a corporation of Delaware Filed Nov. 12, 1964, Ser. No. 410,683 l'Claim. (Cl. 138-178) This invention relates to exhaust systems for internal combustion engines, especially those used in automobiles and trucks and other motorvehicles.

It is an object of the invention to provide an expedient whereby sections of the exhaust system may be more readily bent without resulting disadvantages such as wrinkling, tearing, or flattening of the metal.

The invention accomplishes this and other objects by means of the formation at the radius of bend of a reduced diameter section in the metal. This serves to localize stresses and provide a bank of metal which can flow on the outside of the bend and be readily compressed or contracted on the inside of the bend. This tends to eliminate the undesired wrinkles, dimples, flattening, and other distortions which are normally associated with the bending of a section of an exhaust system.

The invention is illustrated in the accompanying drawings in which:

FIGURE 1 is a slide elevation, schematic, showing an exhaust system to which the invention may be applied;

FIG. 2 is a cross-section through the exhaust system taken prior to bending to the angle indicated in FIGS. 1 and 3;

FIG. 3 is an enlarged side elevation of structure shown in the circle 3 of FIG. 1;

FIG. 4 is a broken away side elevation of another expedient which may be used to localize a bend in a pipe; and

FIG. 5 is a view of the pipe of FIG. 4 taken after it has been bent.

In FIG. 1 the internal combustion engine 1 has an exhaust manifold 3 which delivers exhaust gases to be silenced to -a pipe 5 forming the inlet end of the exhaust system 7. The exhaust system may contain various silencing components and, when used in an automobile, bus, or truck, almost always must be bent at various longitudinal locations to suit the contour of the frame to which it is attached. In the illustrative embodiment there is a silencing device 9 which is connected by means of a pipe 11 to a second silencing device 13 and this empties into a tailpipe section 15 which leads the exhaust gases to atmosphere. It may be assumed for the purpose of this invention that it is necessary to form a bend in the unit 13 at the point indicated in FIG. 1

3,259,149 Patented July 5, 1966 In accordance with this invention, we would provide a reduced section 17 at the desired point of bend in the housing 19 of the silencing unit 13. This may be provided by means of three pinched sections 21 which are formed by compressing the housing 19 in a suitable punch and die or press to form the restricted necked down section 17 and the excess metal being gathered into the U-shaped folds or pinches 21. Preferably, no pinch is formed on the side of the unit which is to be on the inside of the bend.

In bending, as indicated in FIG. 3, the pinches 21 provide support to the metal and the reduced section 17 tends to localize the bending stresses and deformation. Consequently, undesired wrinkling, dimpling, and distortion is minimized.

In FIGS. 4 and 5 a pipe section 31, which may correspond to the unit 13, is shown and in it a rolled down reduced diameter section 33 is formed at the desired point of bend. When bending occurs, as in FIG. 5, it will be localized in the area 33, as indicated.

Modifications may be made without departing from the spirit and scope of the invention.

What is claimed is:

A gas conveying component of an exhaust gas system comprising an elongated tubular housing of substantially uniform diameter along its length, means providing for the bending of one longitudinal section of the housing relative to an adjacent longitudinal section of the housing with a minimum of wrinkling and distortion of the housing comprising a reduced diameter section in the housing located between said two longitudinal sections of the housing, said longitudinal sections extending at an angle to each other, said reduced diameter section serving as an elbow between the two longitudinal sections and including a plurality of pinches extending from the reduced diameter section outwardly to substantially the diameter of the housing, the concave side of the reduced diameter section being free of said pinches.

References Cited by the Examiner UNITED STATES PATENTS 1,302,300 4/1919 Brinkman 181-36 2,047,443 7/ 1936 Starkweather et al. 181-47 X 2,096,260 10/1937 Pavillon 18136 2,157,564 5/1939 Peuthert 179 X 3,081,795 3/1963 Lesser 285-179 X 3,104,735 9/1963 Ludlow et al. 18136 3,133,612 5/1964 Sailler 181--62 X LEO SMILOW, Primary Examiner.

R. S. WARD, Assistant Examiner. 

